/**
 * @author alteredq / http://alteredqualia.com/
 *
 * Focus shader
 * based on PaintEffect postprocess from ro.me
 * http://code.google.com/p/3-dreams-of-black/source/browse/deploy/js/effects/PaintEffect.js
 */

THREE.FocusShader = {

  uniforms : {

    "tDiffuse":       { value: null },
    "screenWidth":    { value: 1024 },
    "screenHeight":   { value: 1024 },
    "sampleDistance": { value: 0.94 },
    "waveFactor":     { value: 0.00125 }

  },

  vertexShader: [

    "varying vec2 vUv;",

    "void main() {",

      "vUv = uv;",
      "gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",

    "}"

  ].join( "\n" ),

  fragmentShader: [

    "uniform float screenWidth;",
    "uniform float screenHeight;",
    "uniform float sampleDistance;",
    "uniform float waveFactor;",

    "uniform sampler2D tDiffuse;",

    "varying vec2 vUv;",

    "void main() {",

      "vec4 color, org, tmp, add;",
      "float sample_dist, f;",
      "vec2 vin;",
      "vec2 uv = vUv;",

      "add = color = org = texture2D( tDiffuse, uv );",

      "vin = ( uv - vec2( 0.5 ) ) * vec2( 1.4 );",
      "sample_dist = dot( vin, vin ) * 2.0;",

      "f = ( waveFactor * 100.0 + sample_dist ) * sampleDistance * 4.0;",

      "vec2 sampleSize = vec2(  1.0 / screenWidth, 1.0 / screenHeight ) * vec2( f );",

      "add += tmp = texture2D( tDiffuse, uv + vec2( 0.111964, 0.993712 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( 0.846724, 0.532032 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( 0.943883, -0.330279 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( 0.330279, -0.943883 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( -0.532032, -0.846724 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( -0.993712, -0.111964 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "add += tmp = texture2D( tDiffuse, uv + vec2( -0.707107, 0.707107 ) * sampleSize );",
      "if( tmp.b < color.b ) color = tmp;",

      "color = color * vec4( 2.0 ) - ( add / vec4( 8.0 ) );",
      "color = color + ( add / vec4( 8.0 ) - color ) * ( vec4( 1.0 ) - vec4( sample_dist * 0.5 ) );",

      "gl_FragColor = vec4( color.rgb * color.rgb * vec3( 0.95 ) + color.rgb, 1.0 );",

    "}"


  ].join( "\n" )
};